Browsing by Author "Choi, J"

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    An evaluation of physician predictions of discharge on a general medicine service.
    (J Hosp Med, 2015-12) Sullivan, B; Ming, D; Boggan, JC; Schulteis, RD; Thomas, S; Choi, J; Bae, J
    The goal of this study was to evaluate general medicine physicians' ability to predict hospital discharge. We prospectively asked study subjects to predict whether each patient under their care would be discharged on the next day, on the same day, or neither. Discharge predictions were recorded at 3 time points: mornings (7-9 am), midday (12-2 pm), or afternoons (5-7 pm), for a total of 2641 predictions. For predictions of next-day discharge, the sensitivity (SN) and positive predictive value (PPV) were lowest in the morning (27% and 33%, respectively), but increased by the afternoon (SN 67%, PPV 69%). Similarly, for same-day discharge predictions, SN and PPV were highest at midday (88% and 79%, respectively). We found that although physicians have difficulty predicting next-day discharges in the morning prior to the day of expected discharge, their ability to correctly predict discharges continually improved as the time to actual discharge decreased. Journal of Hospital Medicine 2015;10:808-810. © 2015 Society of Hospital Medicine.
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    Current conduct of deep hypothermic circulatory arrest in China.
    (HSR proceedings in intensive care & cardiovascular anesthesia, 2013-01) Augoustides, JGT; Patel, P; Ghadimi, K; Choi, J; Yue, Y; Silvay, G

    Introduction

    Deep hypothermic circulatory arrest for adult aortic arch repair is still associated with significant mortality and morbidity. Furthermore, there is still significant variation in the conduct of this complex perioperative technique. This variation in deep hypothermic circulatory arrest practice has not been adequately characterized and may offer multiple opportunities for outcome enhancement. The hypothesis of this study was that the current practice of adult deep hypothermic circulatory arrest in China has significant variations that might offer therapeutic opportunities for reduction of procedural risk.

    Methods

    An adult deep hypothermic circulatory arrest questionnaire was developed and then administered at a thoracic aortic session at the International Cardiothoracic and Vascular Anesthesia Congress convened in Beijing during 2010. The data was abstracted and analyzed.

    Results

    The majority of the 56 respondents were anesthesiologists based in China at low-volume deep hypothermic circulatory arrest centers. The typical aortic arch repair had a prolonged deep hypothermic circulatory arrest time at profound hypothermia. The target temperature for deep hypothermic circulatory arrest was frequently measured distal to the brain. The most common perfusion adjunct was antegrade cerebral perfusion, typically monitored with radial arterial pressure and cerebral venous oximetry. The preferred neuroprotective agents were steroids and propofol.

    Conclusions

    The identified opportunities for outcome improvement in this delineated deep hypothermic circulatory arrest model include nasal/tympanic temperature measurement and routine cerebral perfusion, preferably with unilateral antegrade cerebral perfusion monitored with radial artery pressure and cerebral oximetry. Development and dissemination of an evidence-based consensus would enhance these practice-improvement opportunities.
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    Ecology and the science of small-scale fisheries: A synthetic review of research effort for the Anthropocene
    (Biological Conservation, 2021-02-01) Smith, H; Garcia Lozano, A; Baker, D; Blondin, H; Hamilton, J; Choi, J; Basurto, X; Silliman, B
    © 2020 Elsevier Ltd Human-driven changes to aquatic environments threaten small-scale fisheries (SSFs). Ensuring a livable future for SSFs in the Anthropocene requires incorporating ecological knowledge of these diverse multi-species systems beyond the long-standing reliance on populations, a management paradigm adopted from industrial fisheries. Assessing the state of ecological knowledge on SSFs is timely as we enter the United Nations Decade of Ocean Science and Sustainable Development and with the upcoming International Year of Artisanal Fisheries and Aquaculture. Synthesizing research effort can help identify existing knowledge gaps and relatively well-researched ‘bright spots’ that can inform strategies to achieve global sustainability commitments. Yet trends in ecological research of SSFs are not well understood compared to better-studied industrial fisheries. To address this void, we conducted a synthetic review of SSF publications in ecology journals (n = 302), synthesizing trends in research subjects and methodologies over time. Wide geographic and habitat disparities in the coverage of publications are identified, with marine fisheries in Latin American receiving the greatest coverage while inland and Asian fisheries are understudied relative to the global distribution of SSFs. Bony fish and invertebrates received substantial coverage compared to endangered cartilaginous fishes. Studies have increasingly focused on human dimensions and ecosystem ecology compared to earlier emphasis on population ecology. Methodologically, studies rarely incorporate experiments despite their efficacy in testing interventions. To achieve a ‘wider view’ of fisheries that is reflective of the needs of SSFs in the Anthropocene, future ecological studies should expand their geographic, taxonomic, and methodological breadth to better assess understudied SSF interactions.
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    Iron Age landscape changes in the Benoué River Valley, Cameroon
    (Quaternary Research (United States), 2019-09-01) Wright, DK; MacEachern, S; Ambrose, SH; Choi, J; Choi, JH; Lang, C; Wang, H
    Copyright © 2019 University of Washington. Published by Cambridge University Press. The introduction of agriculture is known to have profoundly affected the ecological complexion of landscapes. In this study, a rapid transition from C3 to C4 vegetation is inferred from a shift to higher stable carbon (13C/12C) isotope ratios of soils and sediments in the Benoué River Valley and upland Fali Mountains in northern Cameroon. Landscape change is viewed from the perspective of two settlement mounds and adjacent floodplains, as well as a rock terrace agricultural field dating from 1100 cal yr BP to the recent past (<400 cal yr BP). Nitrogen (15N/14N) isotope ratios and soil micromorphology demonstrate variable uses of land adjacent to the mound sites. These results indicate that Early Iron Age settlement practices involved exploitation of C3 plants on soils with low δ15N values, indicating wetter soils. Conversely, from the Late Iron Age (>700 cal yr BP) until recent times, high soil and sediment δ13C and δ15N values reflect more C4 biomass and anthropogenic organic matter in open, dry environments. The results suggest that Iron Age settlement practices profoundly changed landscapes in this part of West Africa through land clearance and/or utilization of C4 plants.
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    Iron Age Landscapes of the Benue River Valley, Cameroon
    (Journal of Field Archaeology, 2017-09-03) Wright, DK; MacEachern, S; Choi, J; Choi, J; Lang, C; Djoussou, JD
    The Iron Age settlements of northern Cameroon were dispersed across the landscape, taking advantage of different eco-climatic zones to exploit a variety of natural resources. Situated at the interface of the upper and lower terraces of the Benue River, mound sites in the area around Garoua have occupation histories spanning multiple centuries. The site of Langui-Tchéboua displays evidence for rapid accumulation of sediments approximately 700 years ago, which may have been a deliberate construction strategy that would have allowed the site’s inhabitants to exploit resources in both floodplain and dryland contexts. The combined use of multiple dating methods and micromorphology provide novel insights into both the mechanisms of anthropogenic landscape change and possible motivations governing those choices.